(b. Kangaslampi, Finland, ca. 23 July 1895; d. Helsinki, Finland, 23 October 1971)

geodesy.

Theninth and youngest child of Heikki Heiskanen and Riikka Jurvanen, Heiskanen grew up on a small farm in eastern Finland. He was exceptionally energetic, generous in his opinions of others, and of a deep religious faith. In 1922 he married Kaarina Levanto; they had one daughter. From 1933 to 1936 Heiskanen was a member of the Finnish Diet, wherehe worked to improve the legal status of the Finnish language (Swedish was still the dominant language in some quarters). He also translated and wrote popular works on astronomy with the intent of widening the cultural sphere of his Finnish-speaking countrymen. His work in geodesy was recognized by memberships in seven different academies of science, including the American Academy of Arts and Sciences, and he was an honorary member of the Council of the International Association of Geodesy. The University of Bonn, the Helsinki University of Technology, the University of Uppsala, and Ohio State University awarded him honorary doctorates.

After three years of study, Heiskanen graduated with an M.S. degree from the University of Helsinki in 1919, with top honors in physics, mathematics, astronomy, political economy, and theoretical philosophy. With opportunities more promising in geodesy than in astronomy, his first love, he joined the Finnish Geodetic Institute in 1921 and produced a doctoral dissertation under Ilmari Bonsdorff, “Untersuchungen über Schwerkraft und Isostasie,” in 1924. Bonsdorff’s own studies on the isostatic equilibrium of the earth’s crust may well have provided the initial inspiration...